gdb modes try to insert breakpoint markers too soon

[Bruce Stephens]

There seems to be an irritating interaction between gdb and the gdb
modes in current CVS Emacs (gdb and gdba).

When I set a breakpoint, gdb prints out something like this:

(gdb) break explode
Breakpoint 2 at 0xb7ce73e2: file explode.c, line 241.

and much the same with --annotate=3 and GDB/MI.  i.e., it seems not to
give the full pathname.

My executable and its libraries are compiled with DWARF2 debugging
information, and readelf shows that all of the directories are known.

When execution hits the breakpoint, gdb displays the full pathname.

So when running under Emacs, on setting the breakpoint, Emacs creates
an empty buffer "explode.c" in the directory in which the executable
was linked.  

When I hit the breakpoint, gdb produces two messages:

Breakpoint 2, explode (bind_arg=0xb719c5c0) at explode.c:241

source /local/brs/top-test/build/isode/src/lib/explode.c:241:6202:beg:0xb7ce73e2

(or whatever).  So again Emacs tries to find explode.c in its search
path, and is then told exactly where it is.

What's the best way of dealing with this?  (I suppose disabling
auto-insert would make this less annoying.)

(Creating a .gdbinit file with lots of "directory" commands mostly
works, but unfortunately I have files with identical names (generally
a bad idea, but in this case justified, I think).  In any case, that
seems silly: the information's available; DDD copes without apparent
difficulty.)